Study on Microstructure and Photocatalytic Activity of TiO2 with Surface Modification by SiO2 and Al2O3
-
摘要: 利用硅酸钠、偏铝酸钠对TiO2基体进行无机表面修饰堵塞光辐照二氧化钛产生的电子-空穴,以提高二氧化钛的耐候性能和分散性能。用聚焦光束反射测量仪(FBRM)在线测试粒子表面膜层的生长情况,用X射线衍射(XRD)、光电子能谱(XPS)、扫描电镜(SEM)、透射电镜(TEM)、表面面积(BET)等技术对修饰前后二氧化钛的物相和微/纳结构进行表征分析,结果表明TiO2粒子表面形成了均匀致密的无定型二氧化硅、稳定的勃姆石胶体膜层,填补了空氧位,弥补二氧化钛的光化学活性缺陷;光降解试验结果表明:单硅修饰和硅铝二元修饰的二氧化钛样品的光催化活性降低,降解速率减缓,二氧化钛得到有效的保护。Abstract: Sodium silicate and sodium metaaluminate were used for the inorganic surface modification of TiO2 matrix to block the electron-hole produced by light irradiation on TiO2,finally attempting to improve the weatherability and dispersity of TiO2.The growth of membrane layer on the surface of TiO2 particles was tested online by focused beam reflectance measurement(FBRM).The phase composition and micro/nano structure of TiO2 before and after modification were characterized and analyzed by X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),scanning electron microscope(SEM),transmission electron microscope(TEM) and specific surface area test(BET),respectively.The results show that a uniform and compact amorphous SiO2 and stable boehmite colloid membrane layer have been formed on the surface of TiO2 particles,which can fill the oxygen vacancies and make up the defects of photochemical activity for TiO2.It is also indicated through the test of photodegradation that the photocatalytic activity of TiO2 samples respectively with single silicon and silicon-aluminum binary modifications decrease with slower degradation rates,proving that TiO2 has gotten effective protection.
-
Key words:
- TiO2 /
- surface modification /
- microstructure /
- photocatalytic activity
点击查看大图
计量
- 文章访问数: 22
- HTML全文浏览量: 8
- PDF下载量: 2
- 被引次数: 0